diff --git a/41_snapshots-btrfs b/41_snapshots-btrfs
index aae0b35..392f5f0 100644
--- a/41_snapshots-btrfs
+++ b/41_snapshots-btrfs
@@ -74,6 +74,12 @@ ninit=("${GRUB_BTRFS_NINIT[@]}")
 microcode=("${GRUB_BTRFS_INTEL_UCODE[@]}")
 ## Limit to show in menu
 limit=("${GRUB_BTRFS_LIMIT[@]:-100}")
+## How to sort
+subvolsort=${GRUB_BTRFS_SUBVOLUME_SORT:-"descending"}
+case "${subvolsort}" in
+    ascending)          btrfssubvolsort=("--sort=+rootid");;
+    *)                  btrfssubvolsort=("--sort=-rootid")
+esac
 
 ########################
 ### variables script ###
@@ -158,7 +164,7 @@ snapshots_entry()
 ## List of snapshots on filesystem
 snapshot_list()
 {
-	for snap in $(btrfs subvolume list -sa --sort=-rootid /); do
+	for snap in $(btrfs subvolume list -sa "${btrfssubvolsort}" /); do
 		IFS=$oldIFS
 		snap=($snap)
 		local snap_path_name=${snap[@]:13:${#snap[@]}}
diff --git a/README.md b/README.md
index cdc0dfa..69074e0 100644
--- a/README.md
+++ b/README.md
@@ -54,7 +54,15 @@ Add this lines to /etc/default/grub:
 
 	(Use only if you have custom intel-ucode or auto-detect failed.)
 
+* GRUB_BTRFS_LIMIT=("100")
 
+    (Limit the number of snapshots populated in the GRUB menu.)
+
+* GRUB_BTRFS_SUBVOLUME_SORT=("descending")
+
+    (Sort the found subvolumes by newest first ("descending") or oldest first
+("ascending"). If "ascending" is chosen then the $GRUB_BTRFS_LIMIT oldest
+subvolumes will populate the menu.)
 
 Generate grub.cfg (on Archlinux use grub-mkconfig -o /boot/grub/grub.cfg )